This application claims priority from JP 2003-193981 and JP 2003-193982, both filed on Jul. 9, 2003, the entirety of which is incorporated herein by reference thereto.
1. Field of Invention
The invention relates to a process device, a photosensitive body cartridge, a photosensitive body cartridge assembling method, and an image forming apparatus.
2. Description of Related Art
Conventionally, a drum cartridge having a photosensitive drum is detachably attached to an image forming apparatus, such as a laser beam printer. The drum cartridge includes a lower frame and an upper frame, both of which are made of resin, wherein the upper frame is assembled to the lower frame. The upper frame is provided with a scorotron charging device, and the lower frame is provided with a photosensitive drum that is rotatably supported therein.
The upper frame and the lower frame are commonly assembled to each other by using hooks, which are often used to assemble resin parts to each other. For example, Japanese Laid-Open Patent Publication No. 9-116288 discloses upper and lower frames that are provided with hooks, wherein the upper frame is snapped into a place of the lower frame with a single motion by engaging the hooks with each other.
U.S. Pat. Nos. 6,041,203, 6,330,410, 6,411,789, 6,546,217, and 6,690,903 disclose a conventional image forming apparatus, such as a laser beam printer, to which a process unit is detachably attached, wherein the process unit includes a drum cartridge having a photosensitive drum and a toner cartridge which is accommodated in the drum cartridge and has a developing roller.
As shown in the image forming apparatus in FIG. 10, a process unit 131 is attached to a body frame 133, a shaft 132 of a photosensitive drum 136 provided on the process unit 131 is engaged with guide members 134 provided to inner surfaces of both sides of the body frame 133 and the position of the process unit 131, in a front and rear direction and in an up and down direction, is set with respect to the body frame 133. In addition, both side surfaces of a housing 135 of the process unit 131 in the width direction abut against the respective guide members 134, thereby positioning the process unit 131 in the width direction with respect to the printer frame 133.